1. Field of the Invention
The present invention relates to a suspension board with circuit. More particularly, the present invention relates to a suspension board with circuit mounted on a hard disk drive which adopts an optical assist system.
2. Description of Related Art
In recent years, an optical assist system (an optical assist magnetic recording system) has been known as a magnetic recording system for a hard disk drive or the like. For example, as a suspension board with circuit which adopts the optical assist system, providing an optical waveguide on a suspension has been known.
As such an optical waveguide, an embedded optical waveguide in which a core layer (an optical waveguide) is embedded in a clad layer (an over clad layer and an under clad layer), and a loaded optical waveguide in which an over clad layer is laminated (loaded) on a core layer with its width narrower than the width of the core layer have been known.
There has been proposed that, for example, an embedded optical waveguide is formed in a linear shape and a loaded optical waveguide is formed in a curved shape, and these are connected to each other on a board (cf. Japanese Unexamined Patent Publication No. H07-142699).